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Saturday, May 10, 2014

Aragonite worth billions is being mined in the Bahamas ...Sometimes on a clear day you can't see the bottom

Dredging Money From The Bank

Across the inky-blue Gulf Stream from Florida, near the sheer
edge of the Great Bahama Bank, a new island is emerging from the sea.
Although it bears the appealing name Ocean Cay, this new island is not,
and never will be, a palm-fringed paradise of the sort the Bahamian
government promotes in travel ads. No brace of love doves would ever
choose Ocean Cay for a honeymoon; no beauty in a brief bikini would
waste her sweetness on such desert air.

Of all the 3,000 islands and islets and cays in the Bahamas,
Ocean Cay is the least lovely. It is a flat, roughly rectangular island
which, when completed, will be 200 acres and will resemble a barren
swatch of the Sahara. Ocean Cay does not need allure. It is being
dredged up from the seabed by the Dillingham Corporation of Hawaii for
an explicit purpose that will surely repel more tourists than it will
attract. In simplest terms, Ocean Cay is a big sandpile on which the
Dillingham Corporation will pile more sand that it will subsequently
sell on the U.S. mainland.

The sand that Dillingham is dredging is a specific form of
calcium carbonate called aragonite, which is used primarily in the
manufacture of cement and as a soil neutralizer. For the past 5,000
years or so, with the flood of the tide, waters from the deep have moved
over the Bahamian shallows, usually warming them in the process so that
some of the calcium carbonate in solution precipitated out. As a
consequence, today along edges of the Great Bahama Bank there are broad
drifts, long bars and curving barchans of pure aragonite.

Limestone, the prime source of calcium carbonate, must be
quarried, crushed and recrushed, and in some instances refined before it
can be utilized. By contrast, the aragonite of the Bahamian shallows is
loose and shifty stuff, easily sucked up by a hydraulic dredge from a
depth of one or two fathoms. The largest granules in the Bahamian drifts
are little more than a millimeter in diameter. Because of its fineness
and purity, the Bahamian aragonite can be used, agriculturally or
industrially, without much fuss and bother.

It is a unique endowment. There are similar aragonite drifts
scattered here and there in the warm shallows of the world, but nowhere
as abundantly as in the Bahamas. In exchange for royalties, the
Dillingham Corporation has exclusive rights in four Bahamian areas
totaling 8,235 square miles. In these areas there are about four billion
cubic yards—roughly 7.5 billion long tons—of aragonite. At rock-bottom
price the whole deposit is worth more than $15 billion. An experienced
dredging company like Dillingham should be able to suck up 10 million
tons a year, which will net the Bahamian government an annual royalty of
about $600,000.

On the basis of such big, round figures, the mining of aragonite
seems to be a bonanza operation. In reality it is still a doubtful
venture for both Dillingham and the Bahamas. For Dillingham the big
question is whether the aragonite can be hauled to market cheaply enough
to compete with other suppliers. For the Bahamas the question is more
provocative: What effect will the dredging have on tourism, the major
industry of the islands? Two years ago the Bahamian government made a
study of the tourist trade and found that out of a gross business of
$193 million, about $52 million in wages and profits ended up in
Bahamian hands. The bright beaches and clean waters, the deep reefs and
shallow coral gardens, the game fish of the fiats and the bigger game
fish of the open sea—these are the basic assets of tourism that are apt
to be diminished by a dredging operation.

Dredging is inherently a dirty business. Worthy servant though
it is, a hydraulic dredge simply does not fit into the natural scheme.
The spume created by the cutter of a dredge's maw and the cloudy water
from its discharge pipe are usually more than God's little marine
creatures can tolerate for long. The Bahamian government does not say
much about the aragonite operation, and the Dillingham Corporation says
almost nothing. In this day when all sorts of strident
anti-pollutionists are at the palace gates, reticence on the part of
anyone who is roiling the beautiful Bahamian waters is
understandable—understandable but also deplorable and, in the long run,
stupid. It is human nature to suspect big operators, particularly the
big, quiet ones who—true or not—seem to be making money hand over fist.
By their reticence the Dillingham people are inviting distrust and as a
consequence will probably be charged with crimes they have not
committed.

A mile or two west of the Dillingham Corporation's artificial
island, Ocean Cay, charter boats run the edge of the Gulf Stream in
quest of billfish and tuna. Often, on the ebb tide, cloudy water driven
by prevailing easterly winds moves from the Great Bahama Bank over the
deep. This cloudiness is sometimes caused by long swells born of distant
storms and sometimes by stiff local winds that kick up a fuss in the
shallows. When the Dillingham operation gets going full blast, it will
certainly add to the natural siltiness. In the future the cloudy water
that fishermen encounter may be the work of a Dillingham dredge or it
may be an act of God—or a combination of the two. It will not matter
which. Since fishermen are human, innately suspicious and easily
disgruntled, they will be inclined to blame all the dirty water on
Dillingham.

One of the Dillingham mining concessions completely surrounds
the Joulters Cays, a bonefishing area of proven worth. In the future,
when the water is cloudy and the bonefish do not respond to the lure as
they did of yore, the unlucky anglers will not take God to task; they
will curse Dillingham.

Northwest of Ocean Cay there is a deep and little-known reef
that stretches intermittently for eight miles along a submerged
terrace—a rich and spectacular range. There are narrow canyons and caves
in this drowned scarp, and a profusion of fish large and small. From
the way the living corals spread over the buttresses of ancient rock it
is obvious that the existence of the deep reef depends on a prevalence
of clean water from the Gulf Stream. In the future if the water is often
cloudy and the life of the reef seems to be wasting away, the scuba
divers probably will blame Dillingham.

What effect aragonite mining actually will have on any parcel of
the Great Bahama Bank is still a wild guess since no one has a
sufficient grasp of the problem. Aragonite is fairly heavy stuff,
weighing almost three times as much as water. When stirred up, the
largest granules sink quite rapidly, but in a hundred tons of the
deposit there are a couple of tons of very fine stuff that can stay in
suspension for a week. In that time a large cloud of such material may
travel 30 miles, riding the tide and the whims of the wind, casting
shadows over rich marine areas that seldom suffer under such a pall. In
scientific papers already published on the Great Bahama Bank there is
good information about the movement of water, but none detailed enough
to indicate just how a constant stream of cloudy water is apt to wander
from a given location.

Before any biologist could assess the effect of aragonite
mining, he would have to know a bit about the operation, specifically
how the dredges are to be used and the expected rate of production. The
Dillingham Corporation has declined to give out such information,
maintaining that it might be "a benefit to other suppliers of limestone
on the mainland." Since the corporation has exclusive rights to the
Bahamian drifts, and will be using mining techniques different from
those employed in quarries, it is hard to see how such basic information
could possibly benefit rival suppliers on land.

The Dillingham Corporation claims that the Bahamian government
has already had "ecological studies" made in the area of Ocean Cay and
is having "continuing studies every 90 days." Although this claim is a
slight overstatement, it is true that, at the request of the Bahamian
Ministry of Agriculture and Fisheries, last December Dr. Durbin Tabb of
Miami's Institute of Marine Science did make a two-day survey of the
area. Dr. Tabb was obliged to conduct his investigation on a budget of
$1,500 and without a complete idea of the dredging technique or any
knowledge of the expected rate or continuity of production. On the basis
of his hit-and-run survey, Dr. Tabb concluded that there was no solid
reason why the relatively sterile aragonite drifts should not be mined,
provided the operation was kept under surveillance. He was particularly
concerned with the effect the altered bottom contour might have on
turtle-grass beds in the shallows and what effect the silt from dredging
might have on tuna migration in the deep.

Confronted by concern among biospecialists and by rumbling in
the press, last month the Bahamian Government Information Services put
out their first news release on the aragonite operation. The release
emphasized Dr. Tabb's solid opinion that the aragonite areas are
undersea Saharas of little biological worth. It said nothing about what
might happen when the dust of these submerged Saharas is kicked up by a
dredge and drifts over richer areas downstream.

A large hydraulic dredge with a two-foot throat can easily pick
up 10,000 cubic yards of loose aragonite in a day. In the process it
also sucks up at least six times as much water—roughly 10 million
gallons. When that much silty slurry drains directly back into the sea,
it creates quite a cloud—virtually an endless stream since dredges
usually operate day and night in the interests of economy. Under their
contract with the Bahamas, the Dillingham Corporation has the right to
pile up 12 artificial islands. Logically, in the coming years the
corporation will situate these islands so that dredges with a practical
range of several miles can discharge aragonite and slurry directly onto
them. In such case the cloudiness will certainly be diminished. The
extent of it will depend largely on how much silt the head of the dredge
stirs up and how much remains in solution when the slurry drains, or is
pumped, off the islands.

When a storm of gale force sweeps the Bahamas it produces cloudy
water that may persist over vast areas for as long as a week. A hundred
dredges toiling around the clock could not possibly create a condition
comparable to what the Bahamas get when a hurricane gives them a good
dusting. But there is a difference. The storms of nature are a very
sporadic blight. They have occurred throughout many yesterdays and will
come again tomorrow. The life of the sea, often hanging in fine balance,
has accommodated to that inevitability. Human pollution is a brand-new
burden. The unnatural filth suddenly contributed by man may be only a
pennyweight of the total, but that is sometimes enough to tip the scale.

Drab though it is to the naked eye, a mat of turtle grass on the
sea floor is quite a vital place. On the slimy blades of grass there
are a host of minor organisms that feed on smaller organisms and are
themselves eaten by larger ones. Seven years ago Dr. Donald Moore of
Miami's Institute of Marine Science found, among other things, 28,000
univalve and bivalve mollusks in one square meter of turtle grass. Ten
years ago, using seines and push nets, Victor Springer and Andrew
McErlean of the Florida State Board of Conservation sampled a shoreline
flat of the Florida Keys one day each month for a year. Although the
sand and grass tract they searched was less than two football fields in
area—and the water did not exceed five feet in depth—Springer and
McErlean found 106 species of fish. Grunts, snappers, gobies, porgies,
blennies, wrasse, groupers, barracuda; yellowtail and tripletail;
batfish and lizard fish; goatfish and parrot fish; big-eyed jacks and
little queen triggers; pipefish and filefish and spadefish; bonefish and
surgeonfish; needlefish and thread herring—you name it, Springer and
McErlean found it. A good number of fish they netted in the shallows
were juveniles of species that subsequently take up residence on coral
reefs in deeper water.

Many fish that dwell in, on, or around living coral return to
the grasses behind the reef to forage. Some of these reef dwellers go to
the grass to feed by daylight, others hole up by day and feed at night.
As Dr. Gilbert Voss of the Institute of Marine Science puts it, "toward
evening, between the reef and the turtle grass, there can be a real
traffic jam." While serving at the University of Puerto Rico three years
ago, Dr. Jack Randall examined the stomachs of 5,526 reef fish of 212
species. Curiously, although soft coral polyps are easily ingested, and
should be nourishing, only 10 of the 212 species that Randall examined
had eaten any coral—none of them more than a trace. A preponderance of
the species Randall studied were directly or indirectly dependent on the
turtle-grass beds for nourishment. Sea urchins, which eat turtle grass,
would seem to be too painful a mouthful for almost any fish, yet
Randall found a considerable percentage of urchins in the stomachs of 34
reef species.

In the clear waters of the Bahamas today nursery and feeding
grounds of turtle grass commonly prosper 25 feet down and have been
found at 40 feet. By contrast, for want of light in the turbid waters of
Biscayne Bay around Miami; turtle grass is no longer found much deeper
than 10 feet. To sum it up, when a dredge forces a turtle-grass bed out
of business, the curtain also comes down on a hell of a big variety
show.

It is a common fallacy of man to believe that a profusion of
other forms of life is proof of their prosperity and permanence. Despite
all its variety and oddity, despite its apparent extravagance and
luxuriance, a coral reef is often a desperate place. As viewed through a
diver's mask, magnified to heroic proportion, the finest reefs of the
Bahamas seem to be durable, monumental works of long standing. In truth
the very best of Bahamian reefery is no more than a thin veneer—a very
recent culture of reef corals that has managed to take hold and spread
mostly in the past 5,000 years under conditions that have probably never
been ideal.

When silt particles settle upon them, the polyps of
reef-building coral must work to get rid of the intruders. When the
workload becomes excessive, the polyps are forced to close shop for a
while—and sometimes forever.

Today, largely because of the work of the late Dr. Thomas Goreau
of the University of the West Indies, scientists recognize that turbid
water has still another adverse effect on reef corals. In clear, shallow
water of 10 feet the coral Acropora palmata—one of the primary
reef builders—is usually massive, thick-limbed, on all counts prosperous
enough and strong enough to hold its own against the constant invasion
of borers and the pummeling of the sea. A mere 10 feet deeper, the same
species, if found at all, is much weaker in structure, and growth by
actual measurement is considerably slower. When cloudy water
persistently reduces the light, the coral is, in effect, thrust to a
depth where it cannot build and where it may not survive.

When Astronauts return to earth, the moon dust is vacuumed from
them and they are quarantined for two weeks. The moon dust is reputedly
sterile, but we take no chances. The Dillingham Corporation and the
Bahamian government are willing to gamble with the sterile dust of the
aragonite drifts. When there are so many specialists today who can
minimize the risk, why do they gamble? Primarily, it seems, because
Dillingham prefers to hoard the truth and the Bahamian government is too
skinflinty to pay for a proper investigation. In a day when we are all
getting a trifle sadder and wiser about the environment, this view is as
murky as the waters surrounding Ocean Cay.